Friday, February 13, 2015

Our 'Squidlets' Have Hatched!



Curious about these mysterious opalescent egg casings? So were we! 


On the morning of December 7, 2014, Fort Worden's Ranger Todd found them on his crab pot. Citizen Science Assistant AmeriCorps member, Ashleigh, decided to document the development of these Loligo opalescens, California Market Squid, eggs. Typically laid on sandy or hard substrates on the seafloor bottom, California Market Squid eggs hatch in 3-5 weeks but may require longer in colder water.

Over the course of the first 26 days, the eggs slowly transformed from circular yolks to more distinct shape.  Day 31 brings the initial development of the eye stalks which are then followed by rapid developmental changes.

In the Day 45 photo, one can note the eyes at the base of the mantle, the external yolk sac has decreased in size, and the rapidly developing chromatorphores. These chromatophores, or pigment spots, can be contracted and expanded to allow adult squid to turn from a transparent white to an opaque red-brown. Day 53 shows the yolk sac almost completely gone and the chromatophores expanded.


Finally, Day 55 brought us the moment we have been waiting for! Several 'squidlets' (non-technical term) have hatched!  The hatching of the paralarvae from each capsule was staggered over several days.  One can observe in the final 'Post-hatch Egg Capsule' photo where the juveniles emerged from small slits in their chorions. Using powerful contractions from their mantel, the squidlets entered the waters of our beautiful Salish Sea, fully capable of rapid movement in any direction and sustaining themselves on the remains of their internal yolk sacs. 

Check out this link to see a video of a squidlet mobilizing for their grand entry to the Salish Sea!  You can see the rapid movement of the mantel and changing chromatophores, both essential for life in their abundant and diverse ecosystem.

Thank you to Ranger Todd for sharing these eggs with us back in December! While our eggs took approximately three weeks longer to hatch than the expected 3-5 week gestation period, scientists have noted that development is delayed in colder water. Let's keep stunning creatures like the California Market Squid in mind and continue to inspire conservation of the Salish Sea together! 

Feel free to contact Ashleigh (apilkerton@ptmsc.org) if you have any additional questions!



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